1 Executive Summary

2 Description of the problem

2.0.1 Introduction

Denver Animal Protection is part of the City & County of Denver’s organizational structure and, as such, strives to serve all members of Denver County, an area comprised of 155 square miles (US Census Data) and 53 unique zip codes not associated with a specific company or organization (source, full list).More specifically, Denver Animal Protection (DAP) falls under the umbrella of Denver’s Department of Environmental Health (DEH), which oversees programs related to public health and environment. Within DEH there are seven different divisions (one of which is DAP): Community Health (CH), Public Health Inspection (PHI), Denver Animal Protection (DAP), the Office of Medical Examiner (OME), Environmental Quality (EQ), the Executive Director’s Office (EDO), and the Office of Sustainability (OOS) (source). While DAP garners much public attention, media attention generally focuses on its public facing roles of animal returns to owners and animal adoption (1, 2, 3, 4). However, the shelter also offers a foster program, volunteer opportunities, a weekly vaccination clinic, pet licensing, breed evaluations, wildlife & pest control, and ordinance enforcement. Some of these services are offered at the shelter, while many others are performed by animal control officers who spend much of their time in the field. For example, in addition to enforcing Denver’s leash, pet waste, pet licensing, rabies vaccination, and spay/neuter laws, the field services unit also investigates animal bites, cruelty and neglect claims, and barking dog disturbances. One of DAP’s specific strategies is to “improve public safety and animal welfare by increasing compliance with Denver’s animal codes and improving pet responsibility through proactive outreach efforts” (Mayor’s Proposed 2017 Budget, p. 603). Consequently, with more perfect knowledge of city violation trends and predictors the field services unit will be better able to target public outreach opportunities with current resources, and in turn move in the direction of greater ordinance compliance in the county.

3 Description of the data

3.0.1 Data Summary

Citation data was kindly provided by the City & County of Denver (5, 6) and consists of 32,018 entries of violations issued for a 5 year period from 2012-2017. There are 5 variables represented: zip_code (zip code of owner cited), violation_type (administrative or regular citation), offense (official ordinance number), item_name (description of violation), animal_id (unique animal identifier). Please see the appendix for more detailed information on ordinance numbers and descriptions.

Of these 5 variabless the 2 most important for the purpose of this invesigation are zip_code and offense. A cursory inspection provides the following insights:

  • zip_code - The most frequently occuring zip code (80219) appears ~5,500 times in the data, twice as much as the next highest zip code (80239 with ~2,600 occurences). More importantly, there are 429 distinct zip codes present, an issue that will be addressed later on. The mean number of citations per zip code was 815 for this 6 year period, while the median was 460.
  • offense - The most frequently occuring offense is 8-16 (Leash law - 1st offense) with ~8000 occurences, followed by 8-61 (License required - 1st offense) with ~4,500 occurences. Several of the least issued citations occured less than 10 times in this six year period ( 8-2: Keeping wild or dangerous animals, 8-3: Vaccination, 8-82: Unlawful accumulation of manure, 8-134: Abandonment, 8-140: Trapping of animals, 8-131(B), and 8-153.5(F)). Due to 1st, 2nd, 3rd offenses and rescinded and compliant citations there are 58 types of offenses in the original dataset. The mean number of offenses by type is 520, while the median is 34.

It’s also worth mentioning that animal_id data, though not relevant here, shows that one animal was cited 16 times.

3.0.1.1 Total citations by zip code

3.0.1.1.1 Most cited zip codes

Given the fact that this investigation will focus on geographic considerations, I choose to examine the zip code data first. Several points are worth mentioning with respect to the zip code representation shown in this data. First is the the highest and lowest offending zip codes.

After consulting 3 separate sources (USPS, R’s noncensus package, and R’s choroplethrZip package), the 40 common zip codes across sources were found to be the following:

80012 80014 80123 80202 80203 80204 80205 80206 80207 80209 80210 80211 80212 80214 80216 80218 80219 80220 80221 80222 80223 80224 80226 80227 80230 80231 80232 80235 80236 80237 80238 80239 80246 80247 80249 80264 80290 80293 80294

Zip code discrepancies between the three sources were:

80022 80033 80110 80111 80127 80215 80225 80228 80229 80233 80234 80241 80256 80259 80260 80261 80262 80265 80266 80266 80273 80274 80280 80281 80291 80292 80295 80299

Using sources to triangulate true Denver county zip codes (7, 8), I included (or failed to deem unnecessary) the following zip codes from the questionable list: 80110, 80265, 80266, 80292, and 80295. See the appendix for the final master list of zip codes used.

Using this information, the top ten zip codes based on citation frequency are:

Zip code Number of citations
80219 5480
80239 2583
80204 2093
80205 1852
80211 1843
80216 1581
80223 1528
80220 1360
80210 1336
80249 1123

As we can see in the map, the areas of most concern and subsequent proposed outreach are in the western-center part of the county (80219 in particular), and areas near DIA & bordering Adams County (Stapleton, Montbello, & Green Valley Ranch).

3.0.1.1.2 Least cited zip codes

The lowest offending zip codes are:

Zip code Number of citations
28 80230 262
29 80247 164
30 80214 102
31 80235 92
32 80226 89
33 80110 75
34 80014 65
35 80232 28
36 80012 20
37 80294 1

This map shows an interesting trend: areas on the periphery of the county (bordering Jefferson and Arapahoe Counties) accumulated the least number of citations from 2011-2017, and consequently may be low priority in terms of community outreach. However, it must be noted that the low numbers may in fact be due to other factors (such as less regular patrolling in these areas, for example) over this time period, and not due to the fact that these areas are actually in violation of county ordinances.

3.0.1.1.3 All zip codes

The full table of values is available in the appendix.

3.0.1.2 Citations by type

In addition to investigating areas by pure citation number alone, it also seems prudent to delve into which ordinances are most problematic in the county generally and where they are most problematic specifically.

While original values can be found in the appendix, data cleaning was employed for the interpretation of this variable. For the sake of simplicity all rescinded (“RSCND”) violations or those that came into compliance (“COMP”) were removed from the dataset to avoid overcounting, leaving roughly 26,000 observations. Also logically if we are looking to prescribe interventions to curb infractions in the first place these types of citations wouldn’t be very helpful. Similarly, all “1st”, “2nd”, and “3rd” tags were removed, though those entries themselves were kept.

After sorting the data the top 5 offenses are:

Offense number Frequency
8 8-16 10358
20 8-61 5125
12 8-32 4251
22 8-70/71 2517
17 8-51 2199

3.1 Most frequent offenses: 8-16, 8-61, 8-32, 8-70/71, 8-51

3.1.0.1 8-16 - Leash law

Zip code Frequency
80219 1383
80211 758
80204 676

3.1.0.2 8-61 - License required

Zip code Frequency
80219 956
80239 479
80204 362

3.1.0.3 8-32 - Rabies vaccination required

Zip code Frequency
80219 979
80239 419
80204 301

3.1.1 Denver statistical neighborhoods map

## OGR data source with driver: ESRI Shapefile 
## Source: "statisticalneighborhoods", layer: "statistical_neighborhoods"
## with 78 features
## It has 4 fields
##  [1] Chaffee Park                 Sunnyside                   
##  [3] Highland                     Globeville                  
##  [5] Jefferson Park               Sun Valley                  
##  [7] Valverde                     Athmar Park                 
##  [9] Windsor                      Northeast Park Hill         
## [11] Elyria Swansea               Wellshire                   
## [13] University                   Rosedale                    
## [15] Cheesman Park                Hilltop                     
## [17] Montclair                    Hale                        
## [19] North Park Hill              South Park Hill             
## [21] University Park              Platt Park                  
## [23] College View - South Platte  Overland                    
## [25] Ruby Hill                    Kennedy                     
## [27] Hampden                      Baker                       
## [29] Fort Logan                   Bear Valley                 
## [31] Harvey Park South            Southmoor Park              
## [33] Hampden South                Indian Creek                
## [35] Goldsmith                    Virginia Village            
## [37] Gateway - Green Valley Ranch DIA                         
## [39] University Hills             Harvey Park                 
## [41] Mar Lee                      Westwood                    
## [43] East Colfax                  Auraria                     
## [45] Cory - Merrill               Belcaro                     
## [47] Washington Park              Washington Park West        
## [49] Speer                        Cherry Creek                
## [51] Country Club                 Congress Park               
## [53] City Park                    Clayton                     
## [55] Skyland                      Cole                        
## [57] Marston                      Washington Virginia Vale    
## [59] Barnum                       Barnum West                 
## [61] Villa Park                   West Colfax                 
## [63] West Highland                Sloan Lake                  
## [65] Berkeley                     Regis                       
## [67] Lincoln Park                 City Park West              
## [69] Whittier                     Capitol Hill                
## [71] North Capitol Hill           Civic Center                
## [73] CBD                          Union Station               
## [75] Five Points                  Stapleton                   
## [77] Montbello                    Lowry Field                 
## 78 Levels: Athmar Park Auraria Baker Barnum Barnum West ... Windsor
## OGR data source with driver: ESRI Shapefile 
## Source: "animal_care_and_control_division_boundaries", layer: "animal_care_and_control_division_boundaries"
## with 8 features
## It has 4 fields
## tmap mode set to interactive viewing

Source

3.1.2 Denver Animal Care and Control Division Boundaries

Source

4 Flaws, outstanding questions, and suggestions for future investigation

  • Zip of owner vs. zip where offense was committed
  • How to interpret rescinded and compliant citations
  • Explanation for the large number of non-Denver zip codes
  • Using census data to link zip codes with Denver neighborhoods and thus demographic information
  • Getting more demographic information on owner along with citation information
  • What are the importance of 1st, 2nd, and 3rd violations? What about ordinance violations that are almost never encountered/cited?

5 Appendix

5.0.1 All zip codes and number of offenses

Zip code Number of citations
80219 5480
80239 2583
80204 2093
80205 1852
80211 1843
80216 1581
80223 1528
80220 1360
80210 1336
80249 1123
80207 1021
80206 770
80209 671
80212 639
80222 562
80224 526
80218 515
80221 515
80236 461
80202 444
80231 444
80203 388
80237 353
80238 329
80123 281
80246 281
80227 263
80230 262
80247 164
80214 102
80235 92
80226 89
80110 75
80014 65
80232 28
80012 20
80294 1

5.0.2 Original offense values

##  [1] 8-32 (1ST)    8-61 (1ST)    8-70/71 (1ST) 8-16          8-48         
##  [6] 8-51          8-32 COMP     8-16 (1ST)    8-70/71 COMP  8-32 (2ND)   
## [11] 8-70/71 RSCND 8-61 COMP     8-32 RSCND    8-36 (1ST)    8-63 (1ST)   
## [16] 8-17 (1ST)    8-16 (3RD)    8-70/71 (2ND) 8-55          8-61 RSCND   
## [21] 8-47 (1ST)    8-16 (2ND)    8-131         8-46          8-2          
## [26] 8-132         8-17 (2ND)    8-61 (2ND)    8-121         8-131 (B)    
## [31] 8-47          8-153.5(F)    8-52          8-82 (1ST)    8-91 (1ST)   
## [36] 8-17          8-32 (3RD)    8-61 (3RD)    8-70/71 (3RD) 8-61         
## [41] 8-32          8-82 (2ND)    8-71          8-132 (1ST)   8-2 (1ST)    
## [46] 8-36 (2ND)    8-3 (1ST)     8-91          8-140         8-134        
## [51] 8-63 (2ND)    8-3           8-91 (2ND)    8-140 (1ST)   8-140 (2ND)  
## [56] 8-131(B)(1ST) 8-91 RSCND    8-46 (1ST)   
## 58 Levels: 8-121 8-131 8-131 (B) 8-131(B)(1ST) 8-132 8-132 (1ST) ... 8-91 RSCND
Offense.number Frequency
13 8-16 (1ST) 8039
40 8-61 (1ST) 4425
24 8-32 (1ST) 3696
47 8-70/71 (1ST) 2480
36 8-51 2199
12 8-16 2141
44 8-61 RSCND 1115
27 8-32 COMP 963
43 8-61 COMP 766
39 8-61 681
Offense.number Frequency
30 8-36 (2ND) 2
32 8-46 (1ST) 2
49 8-70/71 (3RD) 2
10 8-140 (2ND) 1
11 8-153.5(F) 1
42 8-61 (3RD) 1
46 8-63 (2ND) 1
54 8-82 (2ND) 1
57 8-91 (2ND) 1
58 8-91 RSCND 1

5.0.3 Denver County Zip Codes

5.0.3.1 Final master list obtained by crosschecking

44 entries:

80012 80014 80123 80202 80203 80204 80205 80206 80207 80209 80210 80211 80212 80214 80216 80218 80219 80220 80221 80222 80223 80224 80226 80227 80230 80231 80232 80235 80236 80237 80238 80239 80246 80247 80249 80264 80290 80293 80294 80110 80265 80266 80292 80295

5.0.3.2 Source: USPS

Original 73 entries in ‘denver, co’ region:

80012 80014 80022 80033 80123 80127 80201 80202 80203 80204 80205 80206 80207 80208 80209 80210 80211 80212 80214 80215 80216 80217 80218 80219 80220 80221 80222 80223 80224 80225 80226 80227 80228 80229 80230 80231 80232 80233 80234 80235 80236 80237 80238 80239 80241 80243 80244 80246 80247 80248 80249 80250 80251 80252 80256 80257 80259 80260 80261 80262 80263 80264 80265 80266 80271 80273 80274 80281 80290 80291 8029380294 80299

Subsequent 53 entries narrowed after eliminating unique zip codes used for a specific company or organization:

80012 80014 80022 80033 80123 80127 80202 80203 80204 80205 80206 80207 80209 80210 80211 80212 80214 80215 80216 80218 80219 80220 80221 80222 80223 80224 80225 80226 80227 80228 80229 80230 80231 80232 80233 80234 80235 80236 80237 80238 80239 80241 80246 80247 80249 80260 80264 80265 80266 80290 80293 80294 80299

5.0.3.3 Source: R package ‘noncensus’

Original 75 entries in ‘denver’ region:

80208 80217 80238 80243 80244 80248 80250 80251 80252 80254 80255 80257 80263 80265 80270 80271 80275 80279 80299 80201 80202 80203 80204 80205 80206 80207 80209 80210 80211 80212 80214 80215 80216 80218 80219 80220 80221 80222 80223 80224 80225 80226 80227 80228 80229 80230 80231 80232 80233 80234 80235 80236 80237 80239 80241 80246 80247 80249 80256 80292 80259 80260 80261 80262 80264 80266 80273 80274 80280 80281 80291 80290 80293 80294 80295

Subsequent 37 entries narrowed using 8031 FIPS (Federal Information Processing Standard) identifier:

80202 80203 80204 80205 80206 80207 80209 80210 80211 80212 80216 80218 80219 80220 80223 80224 80230 80236 80237 80239 80249 80256 80292 80259 80261 80262 80264 80266 80273 80274 80280 80281 80291 80290 80293 80294 80295

5.0.3.4 Source: R package ‘choroplethrZip’

41 entries:

80294 80235 80236 80218 80203 80222 80220 80202 80223 80012 80207 80110 80204 80206 80290 80247 80293 80226 80205 80224 80232 80237 80211 80249 80219 80123 80216 80014 80212 80264 80227 80111 80214 80246 80221 80230 80238 80231 80209 80239 80210

5.0.4 Denver Animal Ordinances

Ordinance.No. Name Description
Sec. 8-134. Abandonment Abandoning an animal is a crime. After leaving notices, Denver Animal Shelter has the authority to impound any animal that appears to be abandoned.
Sec. 8-46. Barking dog nuisance It shall be unlawful for any owner, possessor or keeper of any dog to permit such dog to disturb any person or neighborhood by loud and persistent or habitual barking, howling or yelping. No summons and complaint shall be issued for any violation of this section unless there are at least two (2) or more complaining witnesses from separate households who have signed such complaint. In appropriate cases, as determined by the manager of the department of environmental health or their designee, any animal control officer or police officer who has personally investigated the complaint of a single complainant, and observed problem behavior of the dog with regard to its loud and persistent or habitual barking, howling or yelping, may be the second complaining witness.
Sec. 8-131. Cruelty to animals prohibited It shall be unlawful for any person to needlessly beat, inflict violence upon or kill, overwork, torture or mutilate, or to otherwise treat in a cruel, dangerous or inhumane manner, any animal, or to cause any such acts. It is unlawful to leave an animal in an unattended vehicle either without adequate ventilation or in any manner which subjects the animal to extreme temperatures that are dangerous or detrimental to the animal’s health or welfare.
Sec. 8-47. Disposition of excrement It shall be unlawful for any person who possesses, harbors or is in charge of any dog, cat or other animal not to immediately remove excrement deposited by the animal upon a common thoroughfare, street, sidewalk, play area, park, or upon any private property when permission of the owner or tenant of the property has not been obtained, and such is hereby deemed to be a public nuisance and prohibited. Dog, cat or other animal excrement shall not be placed in storm sewers, but may be placed in trash containers if contained in a closed plastic bag or other closed or airtight nonporous container.
Sec. 8-48. Damaging property It shall be unlawful for any owner, possessor or person who keeps any dog, cat or other animal to permit such animal, whether or not running at large, to destroy, damage or injure any shrubbery, plants, flowers, grass, lawn, fence or anything whatsoever upon any public premises or upon any private premises owned or occupied by a person other than the owner, possessor or keeper of such animal, and the same is hereby declared to be a public nuisance and prohibited.
Sec. 8-52. Dangerous dogs No person who owns, possesses, keeps or exercises any control over a dangerous dog shall permit such dog to be on the premises of such person without being confined. No person who owns, possesses, keeps or exercises any control over a dangerous dog shall permit such dog to go beyond the premises of such person unless the dangerous dog is securely leashed and muzzled, except that a dangerous dog shall not be required to be muzzled when shown in a dog show.
Sec. 8-51. Dog attack or bite No person who owns, possesses, keeps or exercises control over any dog shall do the following: (1) Permit the dog to attack or bite any person or domestic animal not on the premises of such owner, possessor or keeper. (2) Permit the dog to attack or bite any person or domestic animal upon the premises of the residence of such owner, possessor or keeper or upon the premises of any business establishment not then open to the public. It is an affirmative defense to this paragraph if such premises are previously posted at each entrance with a prominent and conspicuous sign warning all persons, in lettering not less than two (2) inches in height, of the dog and if the dog is confined, as that term is defined in section 8-52(b). It is also an affirmative defense to this paragraph that the attack or bite by the dog was necessary to prevent or apprehend a person engaged in committing an act of violence, robbery or theft upon the property. (3) Permit the dog to attack or bite any person or domestic animal upon the premises of any business establishment that is open to the public. It is an affirmative defense to this paragraph that the attack or bite by the dog was necessary to prevent or apprehend a person engaged in committing an act of violence, robbery or theft upon the property.
Sec. 8-31. Failure to vaccinate It shall be unlawful for the owner of any domestic dog or cat over the age of six (6) months to possess, keep or maintain within the city any dog or cat that is not currently vaccinated for rabies in accordance with the provisions of this Code.
Sec. 8-32. Rabies vaccination required It shall be unlawful for any person who owns or harbors any dog or cat in the city to fail to have such dog or cat vaccinated for rabies by a licensed Colorado veterinarian, unless such person presents to the manager a written statement from a licensed Colorado veterinarian that vaccination for rabies would be detrimental to the health of the specific dog or cat. Such vaccination shall be performed on or before the appropriate anniversary date of the initial vaccination. Any person who acquires within the city a dog or cat has a duty to have it vaccinated within thirty (30) days of such acquisition unless the dog or cat has not yet reached an age at which it is safe to vaccinate the animal; provided, however, that in any case the dog or cat must be vaccinated before reaching the age of six (6) months.
8-91 Food producing animals A Food Producing Animal (Restricted Livestock or Fowl) Permit is required for the keeping of up to eight (8) ducks and or chickens combined, and up to two (2) dwarf goats (dwarf goats shall mean Nigerian Dwarf or African Pygmy breeds of goats). Keeping more than eight (8) ducks and/or chickens combined requires a Livestock Permit. Such license shall allow the keeping of the animals by the licensee on a specific property and shall be personal to the licensee and nontransferable. The license shall be valid indefinitely.
Zoning Code 11.8.5 Keeping of Household Animals The Denver Zoning Code regulates how many household pets can be part of a home residence. Violations occur when the number of household pets exceeds 3 dogs, 5 cats, 2 rabbits, or 25 pigeons, or 5 total dogs and cats or 2 domestic honey bee hives.
Sec. 8-2. Keeping wild or dangerous animals prohibited Section 8-2 of the Denver Municipal Code identifies animal species deemed to be wild or dangerous. The owning, possessing, keeping, maintaining, harboring, transporting, or selling of any animal deemed to be wild or dangerous within the City and County of Denver is unlawful and prohibited. Section 8-2-b-7 identifies all specifies of nonhuman mammals that are legal to own within the City and County of Denver.
Sec. 8-16. Leash law Dogs are required to be on a leash and under control of their owner, at all times.
Sec. 8-61. License required It shall be unlawful for the owner, possessor or keeper of any domestic dog (Canis Familiaris) over the age of six (6) months or domestic cat (Felis catus) over the age of six (6) months to keep, maintain, house or have in possession within the city a dog or cat without first having obtained a license for such dog or cat. Dogs or cats over the age of six (6) months purchased, obtained or otherwise acquired shall be licensed within thirty (30) days after such acquisition or, if under, within thirty (30) days after reaching six (6) months of age. Individual licenses shall not be required for dogs or cats being held for redemption or adoption by the municipal animal shelter, an approved shelter owned and operated by a tax-exempt humane organization or a licensed pet shop.
8-91(a) Livestock or fowl permit required A Livestock or Fowl Permit allows an individual to keep livestock or fowl such as, but not limited to, horses, mules, donkeys, burros, cattle, sheep, goats, swine, chickens, geese, ducks, or turkeys on their property.
Sec. 8-132. Neglect of animals prohibited The Denver Animal Shelter has authority to impound any animal that shows signs of neglect (ex. malnourishment).
Sec. 8-55. Pit bulls prohibited It shall be unlawful for any person to own, possess, keep, exercise control over, maintain, harbor, transport, or sell within the city any pit bull.
Sec. 8-136. Poisoning It shall be unlawful for any person to poison any domestic animal in any manner whatsoever with the intent or for the purpose of poisoning such animal.
Sec. 8-121. Quarantine Whenever the owner or possessor of an animal has been notified by any person, whether or not an agent of the manager, or has other cause to believe that the owner’s or possessor’s animal has bitten or in any other way injured a person so as to cause an abrasion of the skin, the owner or possessor shall immediately notify the manager of the incident and shall immediately restrain the suspected animal within the owner’s or possessor’s property for observation by the manager. It shall be unlawful for the owner or possessor to fail to give the required notification, to conceal, hide or remove the suspected animal or in any other way prevent or hinder investigation and observation of the animal by the manager.
Sec. 8-32. Rabies vaccination required It shall be unlawful for any person who owns or harbors any dog or cat in the city to fail to have such dog or cat vaccinated for rabies by a licensed Colorado veterinarian, unless such person presents to the manager a written statement from a licensed Colorado veterinarian that vaccination for rabies would be detrimental to the health of the specific dog or cat. Such vaccination shall be performed on or before the appropriate anniversary date of the initial vaccination. Any person who acquires within the city a dog or cat has a duty to have it vaccinated within thirty (30) days of such acquisition unless the dog or cat has not yet reached an age at which it is safe to vaccinate the animal; provided, however, that in any case the dog or cat must be vaccinated before reaching the age of six (6) months.
Sec. 8-70. Spaying and neutering Spay/neuter is required for dogs and cats living in the City and County of Denver.
Sec. 8-140. Trapping of animals It shall be unlawful to use or set a leg-hold, snare, instant kill-body-gripping trap, or trap which can cause pain, injury or suffering to any animal, except for any mouse or rat snap-type or glue board used for rodent control or any poison. A leg-hold, snare-type or body-gripping trap is any trap which grasps the leg or any portion of such animal and which can injure, harm or cause pain and suffering to the animal.

(Source; More information)

5.0.5 Other sources